1. Field of the Invention
The present invention relates to a control system/method for controlling the operation of a vehicular master clutch, preferably a wet clutch, utilized in connection with a change gear transmission, preferably a manually shifted mechanical change gear transmission. In particular, the present invention relates to a vehicular master clutch control system/method wherein, if vehicle and/or engine speed are below reference values, then clutch position is automatically controlled as a function of throttle pedal displacement, and, if vehicle and/or engine speed are above the reference values, then the clutch is controlled by a manually operated clutch engage/disengage switch, such as a two-position button or lever on the gear shift knob, regardless of the throttle pedal position.
2. Description of the Prior Art
Automated mechanical transmission systems, and automated master clutch control systems therefor, are known in the prior art as may be seen by reference to U.S. Pat. Nos. 4,081,065; 4,361,060 and 4,638,898, the disclosures of which are incorporated herein by reference. Typically, these fully automated systems had various sensors for sensing and providing signals indicative of engine speed (ES), input shaft speed (IS), output shaft speed (OS) and/or throttle position (THL) to a microprocessor based electronic control unit (ECU) which processed the inputs according to predetermined logic rules to issue command output signals to various system actuators such as an engine fuel control, a transmission actuator and/or a clutch actuator. Typically, during start from stop operation, a desired engine speed was calculated as a function of throttle position and compared to actual engine speed to determine if modulation of the clutch was required.
Automated clutch actuators for use with manual transmissions are known in the prior art, see for example, U.S. Pat. Nos. 4,508,625 and 4,828,093, the disclosures of which are incorporated herein by reference. The devices, often referred to as "autoclutches", provide automated start from stop clutch operation and sensed when a manual shift was initiated and completed to provide a relatively unmodulated master clutch disengagement and then reengagement.
While the prior art vehicular master clutch controls are well suited for many uses, they were not satisfactory for all purposes as they were overly complicated and/or expensive for some systems, they did not allow manual clutch engagement/disengagement when shifting on the fly and/or they were not well suited for multiple disc wet clutches.